Deep Brain Stimulation for Treatment Resistant Depression – The Race is On

Implications: Deep brain stimulation (DBS), an FDA approved device treatment for Parkinson’s Disease and essential tremor, has demonstrated quite remarkable findings in several very small pilot studies for treatment resistant depression.   There is great hope among the device makers – namely Medtronics and St. Jude Medical– that this innovative approach may be but a couple years away from their own FDA approvals for refractory depression.   With the FDA’s Investigational Device Exemption (IDE) and clearance to begin enrollment for a DBS/refractory depression trial, St. Jude Medical takes a big step forward.  

Analysis: Though DBS data so far is very limited – but a handful of cases – what's there is among the most compelling interventions in severe psychiatric illness I’ve come across.   In some instances, patients refractory to multiple medication trials and even ECT have shown improvement of symptoms shortly after the device was turned on; even more striking is how symptoms recur when the device is switched off.    

There are many unanswered questions regarding DBS and depression.  Which parts of the brain are best targeted is still being worked out and whether side effects, often neuropsychiatric in nature, will present especially problematic risks for patients with severe psychiatric disorders such as refractory depression.   The pioneering work of Mayberg and Lozano, which forms the neurological and patent basis for the St. Jude trial, targets Brodmann Area 25.   Another area of major interest for resistant depression, also the basis of some case reports, is the nucleus accumbens (considered a key part of the brain’s reward system).     

Vagus nerve stimulation (Cyberonics, Inc.) has been a device disappointment for depression treatment.  But the case material on DBS-treated refractory depression patients is enough to suggest something very different and promising.   If indeed DBS works as well as some case reports show and makes it to market, how it will be accepted among psychiatrists and the public is the next major question.